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Questions in physics

[Done] How much energy does a [tex]$9 x 10^{-8} m$[/tex] wavelength photon have? A. [tex]$5.96 x 10^{-41} J$[/tex] B. [tex]$2.21 x 10^{-18} J$[/tex] C. [tex]$1.988 x 10^{-49} J$[/tex] D. [tex]$7.36 x 10^{-27} J$[/tex]

[Done] A 0.2 kg block of ice at 0°C is dropped carefully into a styrofoam calorimeter cup with an unknown mass of water at 20°C. When thermal equilibrium is reached, the final temperature is measured to be 5°C. What was the mass of water initially in the cup? (Specific latent heat of fusion of ice = 334000 J/kg, specific heat capacity of water = 4200 J/kg K)

[Done] A particle is moving along the [tex]$x$[/tex] axis such that its position is given by [tex]$x=4 t^2-16 t+12$[/tex]. i. Find the instantaneous velocity when [tex]$t=5 s$[/tex]. ii. Find the instantaneous acceleration when [tex]$t =5 s$[/tex]. iii. At what time is the particle stationary?

[Done] Dewayne reviews Kepler's laws by making the table shown. | Kepler's Law | Description | |---|---| | W | The orbital period is related to the average distance from the Sun. | | X | Orbits are ellipses with the Sun at a focus. | | Y | A planet sweeps out equal areas in equal time frames as it orbits the Sun. | Which label belongs in each cell of the table? W: First X : Second Y: Third W: Third X : Second Y: First W: Third

[Done] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Done] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Done] There are no auroras on Venus because it A. Lacks atmospheric oxygen B. Has very high pressure C. Lacks a magnetic field D. Has a very high surface temperature

[Done] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Done] Which factors affect the gravitational force between objects? Check all that apply. A. difference in speed of objects B. direction of movement of objects C. distance between objects D. masses of the objects E. volumes of the objects

[Done] The frequency of a wave does not change as it passes from one medium to another. What will most likely happen if a light wave moves from the air into a solid? A. The wavelength of the light wave will increase. B. The speed of the light wave will decrease. C. The wavelength of the light wave will remain the same. D. The speed of the light wave will remain the same.